I see you are in San Antonio area. I might be willing to do the conversion if you stick with a MB V8 and bring the car to Dallas.

The biggest factor on cost will be your choice of engine. A 430 is not worth doing. A C43 wouldn't be worthe the extra cost as the less expensive 500 engine has the same HP and broader torque curve. A 500 or N/a 55 AMG engine would be my recomendation. The 55 Kompressor will cost WAAAAAAY more and will be hard to keep cool in Texas.

If you really want to go fast, keep it cool and reasonable. I would go with the 500 or n/a 55 with a supercharger from Atwood European. with this set up you can match the 55K but have the advantage of a single belt which allow for the use of C43 cooling components.

With the six speed, the C43 might be an excelent choice or the 500 engine. Better clutches are available.